Python reticulatus

Python reticulatus, also known as the (Asiatic) reticulated python[2] is a species of python found in Southeast Asia. Adults can grow to over 28 feet (8.7 m) in length[3] but normally grow to an average of 10–20 feet. They are the world's longest snakes and longest reptile, but are not the most heavily built. Like all pythons, they are nonvenomous constrictors and normally not considered dangerous to humans. Although large specimens are powerful enough to kill an adult human, attacks are only occasionally reported.

An excellent swimmer, Python reticulatus has been reported far out at sea and has colonized many small islands within its range. The specific name is Latin meaning net-like, or reticulated, and is a reference to the complex color pattern.[4]

Contents

Description

P. reticulatus

Adults can grow to a length of more than 28.5 feet (8.7 m) and are the world's longest snakes.[3][5] However, they are relatively slim for their length and are certainly not the most heavily built.[6] The species Eunectes murinus, the green anaconda, may be heavier.[5]

The largest individual ever accurately measured was Colossus, a female kept at the Highland Park Zoo (now Pittsburgh Zoo) in Pittsburgh, Pennsylvania during the 1950s and early 1960s, with a peak length of 28.5 feet (8.7 m). When she died, April 15, 1963, her body was deposited in the Carnegie Museum of Natural History. At that time she was measured and found to be significantly shorter than the measurements previously published by Barton and Allen. Apparently they had been adding a few extra feet to the measurements to compensate for "kinks", since it is virtually impossible to completely straighten an extremely large live python. Too large to be preserved with formaldehyde and then stored in alcohol, the specimen was instead prepared as a disarticulated skeleton. The hide was sent to a lab to be tanned, and unfortunately it was either lost or destroyed.

Numerous reports have been made of larger snakes, but since none of these have been measured by a scientist nor have the specimens been deposited at a museum, they must be regarded as unproven and probably erroneous. In spite of a standing offer of $50,000 for a live, healthy snake over 30 feet long by the New York Zoological Society, no attempt to claim this reward has ever been made.[3]

Skull diagram

The color pattern is a complex geometric pattern that incorporates different colors. The back typically has a series of irregular diamond shapes which are flanked by smaller markings with light centers. In this species' wide range, much variation of size, color, and markings commonly occurs.

In zoo exhibits the color pattern may seem garish, but in a shadowy jungle environment amid fallen leaves and debris it allows them to virtually disappear. Called a disruptive coloration, it protects them from predators and helps them to catch their prey.[5]

Three sub-species have been proposed,[7] but are not recognized by ITIS. The color and size can vary a great deal between the sub-species described. Geographical location is a good key to establishing the sub-species, each one has a distinct geographical range.

Habitat

The python lives in rain forests, woodland and nearby grassland. It is also associated with rivers and is found in areas with nearby streams and lakes. An excellent swimmer, it has even been reported far out at sea and has consequently colonized many small islands within its range.[5] During the early years of the twentieth century it is said to have been common even in busy parts of Bangkok, sometimes eating domestic animals.[6]

Feeding

Their natural diet includes mammals and occasionally birds. Small specimens—up to 3–4 meters (10–14 ft) long—eat mainly rodents such as rats, whereas larger individuals switch to prey such as Viverridae (e.g. civets and binturongs), and even primates and pigs. Near human habitation, they are known to snatch stray chickens, cats and dogs on occasion. Among the largest, fully documented prey items to have been taken are a half-starved Sun Bear of 23 kilograms that was eaten by a 6.95 m (23 ft) specimen and took some ten weeks to digest, as well as pigs of more than 60 kg (132 lb). As a rule of thumb, these snakes seem able to swallow prey up to ¼ their own length, and up to their own weight.[8] As with all pythons, they are ambush hunters, waiting until prey wanders within strike range before seizing it in their coils and killing via constriction.

Danger to humans

Attacks on humans are rare, but this species has been responsible for several human fatalities, in both the wild and captivity. They are among the few snakes that have been fairly reliably reported to eat people, although only a few cases of the snake actually eating (rather than just killing) a human appear to be authenticated:

Two incidents, apparently in early 20th century Indonesia: On Salibabu, a 14-year-old boy was killed and supposedly eaten by a specimen 5.17 m (c.17 ft) in length. Another incident involved an adult woman reputedly eaten by a "large reticulated python", but few details are known.[9]

Franz Werner reports[3] a case from Burma (or Myanmar) either occurring in the early 1910s or in 1927. A jeweller named Maung Chit Chine, who went hunting with his friends, was apparently eaten by a 6 m (20 ft.) specimen after he sought shelter from a rainstorm in or under a tree. Supposedly, he was swallowed feet-first, contrary to normal snake behavior, but perhaps the easiest way for a snake to actually swallow a human.[10]

In 1932, Frank Buck wrote about a teenage boy who was eaten by a pet 25 ft. reticulated python in the Philippines. According to Buck, the python had escaped and when it was found they could recognize a human child shape inside the snake, which later turned out to be the son of the snake's owner.[3]

On September 4, 1995, Ee Heng Chuan, a 29-year-old rubber tapper from the southern Malaysian state of Johor, was killed by a large reticulated python. The victim had apparently been caught unaware and was squeezed to death. The snake had coiled around the lifeless body with the victim's head gripped in its jaws when it was stumbled upon by the victim's brother. The python, measuring 23 ft long and weighing more than 300 lb, was killed soon after by the arriving police, who required 4 shots to bring it down.[3]

According to Mark Auliya, the corpse of 32-year-old Mangyan, Lantod Gumiliu, was recovered from the belly of a 7m (c.23 ft.) reticulated python on Mindoro, probably in January, 1998.[8]

On October 23, 2008 a 25-year old Virginia Beach woman, Amanda Ruth Black, appeared to have been killed by a 13-foot pet reticulated python. The apparent cause of death was asphyxiation. The snake was later found in the bedroom in an agitated state.[11]

On January 21, 2009 a 3-year-old Las Vegas boy was wrapped by an 18-foot pet reticulated python, turning blue. The boy's mother, who had been babysitting the python on behalf of a friend, rescued the toddler by gashing the python with a knife. The snake was later euthanized because of its fatal wounds.[12]

Considering the known maximum prey size, it is technically possible for a full-grown specimen to open its jaws wide enough to swallow a human child, teenager, or even an adult, although the flaring shoulders of Homo sapiens could pose a problem for a snake with not enough size (<6 meters). The victim would almost certainly be dead by the time the snake started swallowing.

Reproduction

Oviparous, females lay between 15 and 80 eggs per clutch. At an optimum incubation temperature of 31–32°C (88–90 °F), the eggs take an average of 88 days to hatch.[13] Hatchlings are at least 2 feet (61 cm) in length.[6]

Captivity

Increased popularity in the pet trade is due largely to increased efforts in captive breeding and selectively bred mutations such as the "albino" and "tiger" strains. They can make good captives, but keepers should have previous experience with such large constrictors to ensure safety to both animal and keeper. Although their interactivity and beauty draws much attention, some feel they are unpredictable.[14][15] They do not attack humans by nature, but will bite and possibly constrict if they feel threatened, or mistake a hand for food. While not venomous, large pythons can inflict serious injuries, sometimes requiring stitches.

The huge size and attractive pattern of these snakes has made them favorite zoo exhibits, with several individuals claimed to be above 20 feet in length and more than one claimed to be the largest in captivity.[16][17][18][19][20][21] However, due to their huge size, immense strength, aggressive disposition, and the mobility of the skin relative to the body, it is very difficult to get exact length measurements on a living reticulated python, and weights are rarely indicative, as captive pythons are often obese.[3] Claims made by zoos and animal parks are sometimes exaggerated, such as the claimed 49-foot snake in Indonesia which was subsequently proven to be less than 22 feet.[22] For this reason, scientists do not accept the validity of length measurements unless performed on a dead or anaesthetized snake which is later preserved in a museum collection.[3]

The latter two are dwarf subspecies. Apparently, the population of the Sangir Islands north of Sulawesi represents another such subspecies, but it is not yet formally described.[7]

The proposed subspecies dalegibbonsi, euanedwardsi, haydnmacphiei, neilsonnemani, patrickcouperi and stuartbigmorei[23][24] but have not found general acceptance.

A recent phylogenetic study of pythons [25] suggested that the reticulated python as well as the Timor python are more closely related to Australasian pythons than other members of the genus Python, and should therefore be placed in a separate genus, Broghammerus. This is, however, highly controversial as Raymond Hoser was the first to suggest the genus Broghammerus, and most herpetologists question his expertise in the field.